Here's a trick, 'psh' one of the Hershey fonts.ps in /usr/lib/fmfonts. It's now loaded into the window manager. You can 'findfont' and 'setfont' and write the Hershey fonts from within a postscript shell. If you want to pre-load the font from within a postscript shell, look at the user.ps in /usr/people/4Dgifts for an example on loading other .ps files.